Starting mechanism for internal combustion engine



April 5, 1960 T. w; CARRAWAY 2,931,348

STARTING MECHANISM FOR INTERNAL COMBUSTION ENGINE Filed July 1, 1958 2 Sheets-Sheet 1 INVENTORI Tun/ms W CARRAWAY Y: 5W M O U U 0 O April 5, 1960 T. w. CARRAWAY STARTING MECHANISM FOR INTERNAL COMBUSTION ENGINE Filed July 1, 1958 2 Sheets-Sheet 2 INVENTOR 5 77-IOMAS W CARR/1W4) A84 ATTORNEYS STARTING MECHANISM FOR INTERNAL COMBUSTION ENGINE Thomas W. Carl-away, Dallas, Tex.

7 Application July 1, 1958, Serial No. 746,021 6 Claims. (Cl. 123-179) This invention relates to starting mechanism for internal combustion engines, and more particularly to mechanism especially adapted for starting engines used for driving compressors of condensing or cooling equipment, for example equipment of this kind included in air cooling and conditioning installations.

Recently there has been considerable development in the operation of cooling and condensing equipment by internal combustion engines inherently more economical in power cost than electrically driven units. Since cooling equipment usually must be controlled automatically in response to cooling demand, an internal combustion engine driving a condensing or cooling unit must have an eflicient starting mechanism capable of being automatically activated and then automatically deactivated after the engine has been started and has attained normal operating speed.

An objective of the present invention is to provide an improved engine starting mechanism especially suited for use in connection with cooling or condensing equipment, but which has characteristics rendering it advantageous for use in starting internal combustion engines employed for other purposes.

Another object of the invention is to provide an improved engine starting mechanism including means for first enabling normally disabled driving connections between a starting motor and an internal combustion engine, and thereafter activating the starting motor.

Another object of the invention is to provide such a starting mechanism in which the starting motor is activated following the lapse of a predetermined period ensuing upon engagement or enabling of the driving connections between the starting motor and internal combustion engine.

Another object of the invention is to provide starting mechanism of the kind referred to including means, such as a pressure operated switch, for disabling the driving connections between the starting motor and the engine and for stopping the starting motor, in response to building up of pressure in the engine lubricating system. A related object is to provide equipment for ensuring the maintenance of a supply of lubricating oil sufficient not only to perform the normal lubrication function, but also to make certain that the pressure responsive means for disabling the starting mechanism will not fail to function because of any lack of oil in the engine lubricating system.

Other objects of the invention will become apparent from a reading of the following description, the appended claims, and the accompanying drawings, in which:

Figure l is a vertical longitudinal sectional view of cooling and condensing equipment powered by an internal combustion engine equipped with starting mechanism embodying the invention in a preferred form, some parts being shown in elevation and other broken away to show parts in the rear;

starting equipment embodying the invention;

- Figure 3 is a diagrammatic view of some of the parts shown in Figure 2 as viewed from above Figure 2; and

Figure 4 is a view similar to Figure 2, but showing a modified embodiment of the invention.

The invention is particularly applicable for use in connection with condensing and cooling equipment as may be used, for example, in cooling or air conditioning systems. Representative cooling and condensing equipment is shown in Figure 1 as being similar to the equip ment disclosed in the co-pending application of Thomas W. Carraway Serial No. 669,848, filed July 3, 1957. The illustrated equipment includes an evaporative condenser generally designated 1 for cooling and condensing refrigerant compressed by a compressor 2 drivable by an internal combustion engine 3, the engine 3 and compressor 2 being resiliently mounted by springs 4. The compressor 2 receives gaseous refrigerant through an intake pipe 5 from an evaporator coil, not shown, and delivers compressed refrigerant through a pipe 6 to a hot refrigerant gas header 7 from which the hot compressed gas flows downwardly through heat transferring or condensing coils 8 to a liquid cooler bottom header 9 which discharges into a condensed refrigerant receiver 10. A pipe 11 conducts cooled and condensed refrigerant to the expansion coil, not shown.

The evaporative condenser equipment 1 is not conventional in the generally accepted sense of the term, but in some ways is similar to that disclosed in the application for patent of Thomas W. Carraway Serial No. 374,565, filed August 17, 1953, now Patent 2,841,360 dated July 1, 1958. As shown schematically in Figure l of the present application drawings, the evaporative condenser equipment 1 includes an air duct 12 which houses the heat exchanger coils 8 over which a current of air may be forced by a fan or blower 13 mounted within the duct 12 and being drivable by the internal combustion engine 3 through a-pulley and belt drive mechanism generally designated 14. For augmenting the cooling effect of the air forced over the condensing coils 8, provision is made for introducing water in dispersed condition into the duct 12 for extracting heat by evaporation. For this purpose, a liquid disperser including a plurality of rotatable disks, one of which is shown at 15, is mounted in the bottom of the duct 12, and an electric motor 16 is arranged to drive the disks 15. Rotation of the disks causes them to pick up water or other evaporative liquid from a pan or reservoir 17 provided in the bottom part of the duct 12, and throw the liquid off in the form of a fog or mist into the part of the duct between the fan 13 and the condensing coil 8 in a manner to envelop the coil and maintain it wet. Preferably, a deflector 18 is provided for directing liquid thrown olf by the disks 15 toward the coil 8 and away from the blower or fan 13. Battles or louvers 19 are arranged in the outlet end of the duct 12 for intercepting relatively large drops of liquid which may have passed the coil 8, and for returning the intercepted liquid to the pan or reservoir 17.

Any suitable means such as a float controlled valve 20 may be provided for automatically controlling the adding of make-up liquid from a supply pipe 21 to the reservoir 17 for replacing liquid which has been dissipated by evaporation during normal operation of the equipment.

Dispersion of the evaporative liquid in the condition must conductive to eflicient cooling by evaporation may be promoted by maintaining the liquid free of foreign matter and at a predetermined constant level in the tank 17. For accomplishing this purpose in concert with the float valve 20, a liquid overflow device comprising a funnel shaped skimmer 22 at the upper end of an giverfiow pipe 23 is mounted in the bottom ofth duct 12 with the top of the skimmer 22 at the level desired to be maintained. The construction of the skimmer 22 in the shape of a funnel with a widely spread out upper edge or rim results in overflow liquid passing into the skimmet in a thin film or sheet extending around the skimmer, which serves efficiently to drain off floating debris or impurities from the top of the liquid in the pan or reservoir 17. This efficient removal of particulate matter minimize the formation of deposits on the condensing coils 8, and thus enables the latter to remain in eliicient operating condition with a minimum loss of time for cleaning the coils.

The internal combustion engine 3 is cooled by the same fan 13 as cools the compressed hot refrigerant and a liquid coolant circulation system. As indicated schematically in Figure l, the engine is provided conventionally with a water jacket 24 which receives cooling water from a supply tank 25 through a pipe 26. Cooling water is drawn through the water jacket 24 by a pump 27 and forced through a pipe 28 to cooling or radiator coils 29 extending across the duct 12 between the condenser coils 8 and the louvers 19. The heat exchanger 8 is positioned on the upstream side of the radiator 29 so that moistened air which has passed over the condenser coils will flow in contact with the engine cooling water radiator 29 before being discharged from the duct. The volume of air delivered by the fan 13 and the cooling efiect of the evaporative liquid delivered by the disperser 15 are sufficient to carry the load of cooling the engine coolant in the radiator 29 as well as cooling and condensing the refrigerant in the coils 8. Water which has been cooled in the radiator coils 29 is forced through a pipe 30 back to the cooling water tank 25 by the pump 27.

The engine 3 is provided with a pressure feed lubricating system including a pump 31 mounted within the engine crankcase 32, the latter serving as a lubricant reservoir in which lubricating oil is maintained at a level indicated by the line OL in Figure 1.

Preferably, the engine 3 is coupled to the compressor 2 by a speed responsive clutch 33 which provides driving connection of the engine to the compressor only after the engine has attained a predetermined operating speed.

Since in many instances condensing and cooling equipmct of the kind described above is used in homes, it is especially important that the mechanism for starting the internal combustion engine in response to a demand for cooling be as trouble free as possible, and the present invention relates particularly to the engine starting mechanism which fills this requirement. Considered generally, the starting mechanism includes a normally inactive starting motor, normally inoperative or disengaged drive transmitting connections, e.g. gearing interposed between the starting motor and the internal combustion engine, and Control means which may be operated either manually or thermostatically for engaging the gearing before the motor is started, for then starting the motor in response to or after engaging of the gearing, and for disabling the starting mechanism when the engine has attained its normal operating speed. In the form shown in Figures 1, 2 and 3, an electric starting motor 34 is housed within a casing 35 secured to the engine crankcase 32, as shown in Figure 1. The diagrammatic views, Figures 2 and 3, show the motor 34 as being arranged to transmit drive through an overrunning clutch 36 to a shaft 37 splined at 38 to receive a starting pinion 39 for sliding movement on the shaft 37 and for rotation in unison with the shaft. Normally, the pinion 39 is positioned to the left as shown in Figures 2 and 3, so as to be disengaged from a ring gear or starting gear 40 on the internal combustion engine shaft. Operating means generally designated 4-1 for moving the pinion 39 to the right along the shaft 37 and into engagement with the starting gear 4t) includes a yoke 42, the arms of which are formed or provided with forks 43 equipped with anti-friction balls 44 engaging opposite faces of a flange 45 on the pinion 4 39. A spring 46 interposed between a fixed bracket 47 and a disk 48 on the yoke 42 urges or biases the yoke toward the left so as yieldably to maintain the pinion 39 in its leftmost or disengaged position.

Mechanism for moving the pinion 39 toward the right and into engagement with the starting gear 40 includes a solenoid device 49 comprising a winding or coil 50 and a plunger 51 secured to the yoke 42. When the solenoid coil 50 is energized, the plunger 51 is drawn toward the right against the bias of the spring 46 for moving the PilllOfi 39 into mesh with the ring gear 49.

Electrical means for energizing the electromagnetic device, i.e. the solenoid 49, includes main or high voltage power line conductors 52 and 53, the conductor 52 extending directly to one end of the solenoid winding 50, and the conductor 53 leading to a normally closed pressure operated cut-off switch 54 from which a conductor 55 leads through a normally open relay switch 56 to a conductor 57 which extends to the other end of the solenoid coil 50.

Energizing of the electromagnetic means or solenoid 49 through the circuit described above is effected by closing of the switch 56 through the medium of its relay coil 55, which preferably is energized by a low voltage auxiliary or control circuit. As shown in Figure 2, the low voltage circuit is powered by a transformer 59 the primary winding of which is connected to the high voltage lines 52 and 53 by means of conductors 60 and 61. ()ne end of the transformer secondary winding is connected through a conductor 62 to one terminal of the relay coil 58, the other terminal of which leads through a conductor 63 to a start initiating control switch 64 which may be manually, thermostatically, or otherwise suitably operated. The switch 64 is connected through a conductor 65 to the other end of the transformer secondary winding.

In operation, the transformer primary winding normally is energized since the cut-off switch 54 normally is closed, so that when the control switch 64 is closed the relay coil 58 will be energized by the low voltage circuit, thus closing the switch 56. The normally closed switch 54 still being closed and the normally open switch 56 having thus been closed, the solenoid coil 50 will be energized by a circuit comprising the conductor 52, the coil 50, the conductor 57, the closed switch 56, the conductor 55, the closed switch 54, and the power supply conductor 53. Energizing of the coil 50 will draw the solenoid plunger 51 toward the right to move the pinion 39 into meshing engagement with the starting gear 40. Since the pinion is moved into engagement with the starting gear before activation of the starting motor 34, the pinion will not be rotating at the time of meshing, and damaging or wearing of the pinion and gear teeth will be prevented or minimized.

In the embodiment shown in Figures 2 and 3, starting of the motor 34 following engagement of the pinion 39 with the starting gear 40 is effected by closing of a switch generally designated 66 is response to the movement of the solenoid plunger 51 which shifts the pinion into engagement with the gear. The switch 66 is included in a motor energizing circuit including a branch conductor 67 leading from the power supply conductor 52 to the motor, a conductor 68 leading from the motor to a fixed contact 69 of the switch 66, a further fixed contact 70, a conductor 71 leading to the conductor 57, the normally open switch 56, the conductor 55, the normally closed switch 54, and the power supply conductor 53. Also included in the motor energizing circuit is a movable switch contact bar 72 carried by the solenoid plunger 51.

When the switch 64 has been closed and the solenoid plunger 51 moved to the right to engage the pinion 39 with the gear 40 as previously explained, the movable switch contact bar 72 bridges the fixed contacts 69 and so as to close the motor circuit to activate the motor and turn over the engine shaft and start the engine.

In accordance with the invention, starting of the internal combustion engine and its attainment of a predetermined operating speed is effective through the building up of pressure in the engine lubricating system for completely disabling the starting mechanism and restoring the parts to normal condition even though the switch 64 be held closed after the engine has been started. The preferred mechanism for disabling the starting equipment includes a movable contact bar 73 of the normally closed cut-off switch 54 and a sylphon bellows 74 connected to the contact bar 73 and communicating through a tube 75 with the pressure feed lubricating system, for example at the pump 31 as shown in Figure 1. When the engine has attained a normal operating speed and the lubricating oil pressure has been built up to a predetermined value,

the sylphon bellows 74 will expand to raise the contact bar 73 and thusopen the circuit including the motor 34, and open the circuit including the solenoid winding 50 and the circuit including the primary winding of the transformer 59. This will supersede the control effected by the start initiating switch 64, and thus completely disable the entire starting equipment, stopping the motor 34, and enabling the spring 46 to disengage the pinion 39 from the gear 40. v

In the modified starting mechanism and control arrangement shown in Figure 4, the circuit for energizing the solenoid 49 to move the pinion 39 into mesh with the gear 40 is the same as the solenoid energizing circuit described with reference to Figure 2, and the parts constituting this circuit accordingly are designated by reference characters the same as those identifying like parts in Figure 2. However, in the arrangement shown in Figure 4 the circuit for energizing the motor 34 is not closed by a mechanically operated switch such as the switch 66 shown in Figure 2, but instead is closed by operation of a separate motor starting switch 76 which is closed under the control of a thermally responsive time delay switch 77 following the lapse of a predetermined period ensuing upon closing of the main control or start initiating switch 64. The motor starting switch 76 is closable by a relay coil 79 one end of which is connected to the transformer 59 through the conductor 62. The other end of the relay coil 79 is connected through a conductor 80 and the thermally responsive switch 77 to the conductor 63 which leads through switch 64 and conductor 65 to the other end of the transformer secondary winding.

When the switch 77 is closed in the manner hereinafter described, a circuit for energizing the relay coil 19 and closing the motor starting switch 76 is completed to include the transformer secondary winding, conductor 62, coil 79, conductor 80, closed switch 77, conductor 63, closed switch 64, and conductor 65 which leads back to the other end of the transformer secondary winding.

The switch 77 is normally open and is positioned in heat transferring relation to a heating coil element 81 so that when the latter is energized and the switch 77 consequentially heated, the switch will close and enable the circuit through the relay coil 79 for closing the motor starting switch 76. Energizing of the heating element 81 is controlled by the switch 64 which, when closed, completes a circuit extending from one side of the transformer secondary through the conductor 62, heating element 81, conductor 63, switch 64, and conductor 65 leading back to the other end of the transformer secondary winding. After closing of the switch 64 with immediate energizing of the solenoid 49 and meshing of the pinion 39 with the gear 40 there will be a lapse of a predetermined period, say about one or two seconds, before the heating effect of the coil 81 will cause the switch 77 to close, in turn effecting closing of the switch 76 and starting of the motor 34. Because of the lapse of time required for this operation there will be no possibility that the motor 34 will start to rotate the pinion 5 39 before the latter has been engaged with the starting gear 40.

The gear engaging and motor starting mechanism.

shown in Figure 4 is disabled when the engine has attained normal operating speed by means similar to that described with reference to Figure 2. Thus, when the engine 3 has been started and the pressure in its lubricating system has been built up to a predetermined value, oil under pressure acting through the tube 75 will expand the bellows 74 and open the cut-off switch 54, thereby enabling the spring 46 to restore the pinion 39 to its disengaged position, and also breaking the motor circuit and the. circuit which energizes the heating element 81.

Inasmuch as in both disclosed embodiments of the invention disabling of the engine starting mechanism is dependent upon building up of pressure in the engine lubricating system, it is important that the'lubricating oil in the engine crankcase or reservoir 32 be maintained with certainty at such a level that there will be no possibility of failure to build up pressure after the engine has been started. In accordance with the invention, lubricant supply equipment includes a supply tank 82 large enough to hold a reserve supply of lubricating oil sufficient to till the needs of a year or more of normal operation. The tank 82 is connected to the oil reservoir 32 through equipment automatically controlling the supply of make-up oil to the reservoir. vIn the form shown in Figure 1, an outlet pipe,83 leading from the bottom of the supply tank 82 is provided with an 'exteriorly threaded extension pipe 84 having threaded engagement with the top wall of a control chamber 85 carried by a bracket 86 which may be supported in any suitable mariher, for example on the duct 12. Rotation of the exten-' sion pipe 84 relatively to the control chamber will adjust the position of the lower end of the pipe 84 to a selected level corresponding to the oil level required to be maintained in the engine crankcase 32. A look nut 87 on the pipe 84 may be tightened for holding the parts in adjusted positions. An outlet pipe 88 at the bottom of the control chamber 85 leads through a flexible conduit or hose 89 to the engine crankcase or reservoir 32. A valve 90 in the pipe 83 may be turned off when the supply tank 82 is being filled. The control chamber 85 is provided with a vent tube 91, and the supply tank 82 is equipped with an air-tight filler opening sealing cap 92-.

In operation, as oil in the engine lubricating system is normally consumed and the oil level OL thereby tends to lower, tending to lower the oil level in the control chamber 85, oil will be permitted to descend from the supply tank 82 to restore the oil level in the chamber 85 and consequently restore or maintain the level OL in the engine crankcase. In'this way, maintenance of the normal oil level in the engine crankcase is assured so that there will be no possibility of failure of operation of the starting mechanism disabling switch 54 attributable to lubricant fluid pressure failure. a 7

As shown in Figure 1, the engine3 maybe provided with a shaft extension 93 equipped with a magnetic clutch 94 for driving a shaft 95 which may be coupled to auxiliary mechanism or may be used, for example, for driving some part of the cooling and condensing equipment directly from the engine 3. Thus, if desired, the electric motor 16 for driving the liquid disperser 15 could be dispensed with and the disperser could be driven from the engine 3 through the magnetic clutch 94 and drive connections, not shown, between the shaft 95 and the dis,- perser 15. I

The constructions shown embody the invention in preferred forms, but it is intended that the disclosure be illustrative rather than definitive, the invention being defined in the claims.

I claim:

1. In starting mechanism for an internal combustion engine having a starting gear and a prcssure feed lubricating system, a starting motor; a motor driven shaft; a pinion splined on said shaft to slide thereon from a first position in which said pinion is disengaged from said starting gear to a second position in which said pinion is engaged with said starting gear; spring means biasing said pinion to its first position; electromagnetic means adapted when energized to move said pinion against the bias of said spring means to said second position; means including start initiating means for energizing said electromagnetic means to cause the latter to move said pinion to its second position; time delay means operable after lapse of a predetermined period following energizing of said electromagnetic means for activating said starting motor; and means responsive to building up of pressure in said engine lubricating system after the engine has been started for superseding said start initiating means for tie-energizing said electromagnetic means and restoring said time delay means to its normal condition for deactivating said starting motor.

2. In starting mechanism for an internal combustion engine having a starting gear and a pressure feed lubricating system, a starting motor; a shaft; an overrunning clutch operatively coupling said motor to said shaft; a pinion splined on said shaft to slide thereon from a first position in which said pinion is disengaged from said starting gear to a second position in which said pinion is engaged with said starting gear; spring means biasing said pinion to its first position; electromagnetic means adapted when energized to move said pinion against the bias of said spring means to said second position; means including star initiating means for energizing said electromagnetic means to cause the latter to move said pinion to its second position; time delay means operable after lapse of a predetermined period following energizing of said electromagnetic means for activating said starting motor; and means responsive to building up of pressure in said engine lubricating system after the engine has been started for superseding said start initiating means for tie-energizing said electromagnetic means and restoring said time delay means to its normal condition for deactivating said starting motor.

3. in starting mechanism for an internal combustion engine having a starting gear and a pressure feed lubricating system, a starting motor; a motor driven shaft; a pinion splined on said shaft to slide thereon from a first position in which said pinion is disengaged from said starting gear to a second position in which said pinion is engaged with said starting gear; spring means biasing said pinion to its first position; electromagnetic means adapted when energized to move said pinion against the bias of said spring means to said second position; means including start initiating means for energizing said electromagnetic means to cause the latter to move said pinion to its second position; motor starting means including a normally open thermally responsive electric switch closing of which is effective for starting said mo'tor; an electric heater element energizable automatically when said electromagnetic means is energized and being in heat transferring relation to said normally open thermally responsive electric switch for closing of the latter after lapse of a predetermined period following energizing of said heater element; and means responsive to building up of pressure in said engine lubricating systern after the engine has been started for superseding said start initiating means for (is-energizing said electromagnetic means and restoring said motor starting means including said normally open thermally responsive switch to its normal condition for thereby stopping said motor.

ant ers 4. In starting mechanism for an internal combustion engine having a starting gear and a pressure feed lubrieating system, an lectric starting motor; a motor driven shaft; a pinion splined on said shaft to slide thereon from a first position in which said pinion is disengaged from said starting gear to a second position in which said pinion is engaged with said starting gear; spring means biasing said pinion to its first position; electromagnetic means adapted when energized to move said pinion against the bias of said spring means to said second position; means including start initiating means for energizing said electromagnetic means; a normally open electrically operated relay switch in circuit with said motor; a normally open thermally responsive switch operable for closing said relay'switch to start said motor; an elec tric heater element in heat transferring relation to said normally open thermally responsive switch; means for energizing said heater element when said electromagnetic means is energized whereby to effect closing of said thermally responsive switch and closing of said relay switch; and a cut-01f switch in circuit with said motor and said electromagnetic means operable in response to building up of pressure in said engine lubricating system after the engine has been started for superseding said start initiating means for de-energizing said electromagnetic means and stopping said motor.

5. In a starting mechanism for an internal combustion engine, an electric starting motor; normally inoperative drive transmitting connections adapted to be rendered operative for transmitting drive from said motor to said engine; electromagnetic means adapted when energized to render said drive transmitting connections operative; a normally open relay switch in circuit with said motor; a normally open thermally operable switch controlling operation of said relay switch; an electric heater element in heat transferring relation to said normally open thermally operable switch; and means for energizing said electromagnetic means and said heater element for first rendering said drive transmitting connections operative and then closing said relay switch after lapse of a predetermined period required for transfer of sufiicient heat from said heating element to said normally open thermally responsive switch for closing the latter.

6. In combination, an internal combustion engine having a lubricating oil reservoir and a pressure feed lubricating system; a starting motor; normally inoperative drive transmitting connections adapted to be rendered operative for transmitting drive from said motor to said engine; means for rendering said drive transmitting connections operative and for starting said motor; pressure responsive means responsive to building up of pressure in said engine lubricating system after the engine has been started for restoring said driving connections to inoperative condition and for stopping said motor; and equipment for automatically maintaining the oil level in said reservoir required to ensure operation of said pressure responsive means.

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